Medicare Advantage's $1 Trillion Overpayment Problem: What It Means for Your Premium If You're Weighing Medigap Plan G in 2027
The number that should change how you compare plans this fall
You're probably going to open your Annual Notice of Change letter sometime in September, skim it for the new premium, and move on. This year, skim slower. A new analysis from the Committee for a Responsible Federal Budget (CRFB), highlighted in Medicare Rights Center's Evidence of MA Overpayment Continues to Mount, projects that Medicare Advantage overpayments could total $1 trillion over the next decade — money paid to insurers above what it would have cost to cover the same beneficiaries under Original Medicare.
That figure doesn't sit in a government ledger and stay there. Overpayments get funded, in part, by everyone's Part B premiums, and CMS has already signaled rising MA benchmark payments for 2027. Whether you're on a $0-premium Medicare Advantage plan or paying $178 a month for Medigap Plan G, this is one of those stories where the policy detail becomes a line item on your bill within a year or two. If you haven't re-run your own numbers since you enrolled, this is the year to do it — and I'll walk you through exactly what to check.
Decision moment: three things converging on your 2027 costs
Before the math, here's what's actually happening and why it matters to your enrollment choice:
- MA overpayments are accelerating, not shrinking. CRFB's projection builds on Medicare Trustees data showing MA enrollment and per-beneficiary costs both rising faster than Original Medicare spending — a gap that CMS's benchmark methodology hasn't closed.
- The IRA's Part D protections are the thing standing between you and a return to unlimited drug spending. Medicare Rights Center's What's at Stake in 2026 piece is a reminder that the $2,000 out-of-pocket cap, the elimination of the coverage gap ("donut hole"), and Medicare's drug price negotiation authority are relatively recent — and not universally guaranteed to stay untouched.
- Pharmacy benefit managers are under direct legal fire. Florida's attorney general sued Express Scripts and Prime Therapeutics over alleged price-fixing tied to their rebate-aggregation deal — a reminder that the price you pay at the counter is set by parties you never chose and can't negotiate with directly.
None of these stories tells you what to do. But stacked together, they tell you that the gap between "what I'm paying now" and "what I should be paying" is probably wider than you think — on both the MA side and the Part D side.
What $1 trillion in overpayments actually means for your premium
Here's the mechanism, because "trillion" is an abstraction until you connect it to your mailbox. Medicare Advantage insurers are paid a per-beneficiary benchmark rate by CMS, adjusted for regional cost and a "risk score" reflecting how sick CMS believes each enrollee to be. CRFB's analysis — echoing years of MedPAC findings — argues that risk scores in MA run systematically higher than the same population would generate under Original Medicare, without a corresponding increase in actual care delivered. That gap is the overpayment.
Insurers use part of that margin to fund the extras that make $0-premium MA plans attractive: dental allowances, gym memberships, over-the-counter credits. When CMS tightens benchmark growth or Congress revisits risk-adjustment rules (both live possibilities discussed in our piece on the CMS 2027 payment rate increase and its effect on your premiums), those extras are usually the first thing trimmed — not the headline premium, which insurers protect to stay competitive in enrollment comparisons. That means the true cost of an MA plan can rise through reduced benefits and narrower networks well before it shows up as a premium increase you'd notice on a renewal notice.
Worked example — a $0-premium MA plan quietly getting more expensive:
| Year | Monthly premium | Dental allowance | OTC credit | Effective annual value lost |
|---|---|---|---|---|
| 2026 | $0 | $2,000/yr | $600/yr | — |
| 2027 (hypothetical benefit trim) | $0 | $1,200/yr | $300/yr | $1,100 |
Your premium didn't move. Your effective cost of coverage went up by $1,100 — money you'll now spend out of pocket for the dental work and OTC items the plan used to cover. This is the kind of shift that never appears in a headline premium comparison, which is exactly why running the full-benefit math matters more than the sticker price. Toravine tracks these year-over-year benefit changes across plans so you're not relying on last year's brochure to make this year's decision.
The $2,000 Part D cap: what it's protecting you from, in real dollars
The IRA's Part D redesign is easy to take for granted if you've only been on Medicare since it took effect. Here's what it replaced, per Medicare Rights Center's What's at Stake in 2026: before 2025, a beneficiary with high drug costs could pay thousands beyond the coverage gap with no ceiling. Now, once your out-of-pocket spending hits $2,000 in a calendar year, Part D picks up 100% of covered drug costs for the rest of the year.
Worked example — a beneficiary on a specialty drug regimen:
- 2026 Part D deductible: $590
- Coinsurance phase: 25% of drug costs after deductible, until you hit the $2,000 out-of-pocket cap
- A beneficiary on a $1,200/month specialty drug (list price) would blow through the deductible in January and reach the $2,000 cap by roughly March
- Total annual out-of-pocket exposure: $2,000 — versus an estimated $8,000–$11,000 under pre-IRA rules for the same drug regimen
That's the protection currently in place. It's also the protection Medicare Rights Center flags as politically contested heading into 2026 budget negotiations — not because anyone has proposed repealing the cap outright, but because funding mechanisms for it (including manufacturer rebates and the negotiation program) remain live policy fights. If you want the deeper mechanics of how tier placement interacts with that cap, our breakdown of the $2,000 out-of-pocket cap and how MA overpayments could raise your 2027 drug plan premium walks through the funding tension directly.
The PBM lawsuit and why your formulary price isn't really a "price"
Florida's suit against Express Scripts and Prime Therapeutics alleges the two rival pharmacy benefit managers colluded through a rebate-aggregation arrangement in ways that inflated what patients and plans pay at the pharmacy counter. Whatever the legal outcome, the underlying structure it's challenging is the same one that sets your formulary tier and copay today: PBMs negotiate rebates with manufacturers, decide which drugs land on which tier, and pocket a spread most beneficiaries never see itemized.
This matters for your plan comparison because two Part D plans with identical premiums can have wildly different real costs for the same drug, purely based on which PBM they use and how that PBM's rebate deal is structured.
| Drug | Plan A (Tier 2, $15 copay) | Plan B (Tier 3, $47 copay) | Plan C (non-preferred, 40% coinsurance) |
|---|---|---|---|
| Generic statin | $15/month | $47/month | ~$22/month (on a $55 drug) |
| 12-month cost | $180 | $564 | $264 |
Same molecule, same pharmacy chain in some cases — a $384 annual swing based entirely on formulary placement decisions made by the PBM behind each plan. This is exactly the trap we detailed in how tier changes and prior authorization determine whether you pay $15 or $400 for the same medication. The Florida suit is a sign that regulators are starting to treat this as more than an industry quirk — but until enforcement changes anything, the only defense you have is re-checking your specific drug list against specific plan formularies every single year.
Putting it together: MA vs Medigap Plan G, with the overpayment and PBM risk priced in
Here's the comparison that actually matters for your enrollment decision this fall — not "MA vs Original Medicare" in the abstract, but your specific numbers against both the overpayment risk and the drug pricing risk.
| Factor | Medicare Advantage ($0 premium) | Original Medicare + Medigap Plan G (~$178/mo) |
|---|---|---|
| Annual premium | $0 | ~$2,136 |
| MOOP / out-of-pocket cap | Up to $8,850 (in-network) | Effectively near-$0 after Part B deductible ($257) |
| Exposure to benefit trims from overpayment corrections | High — extras funded by benchmark margin | None — Medigap benefits are contractually fixed |
| Part D drug cost exposure | Depends on plan's PBM/formulary | Depends on separate Part D plan's PBM/formulary |
| IRMAA exposure (if income triggers it) | Applies to Part B/D portions | Applies to Part B/D portions |
The MA column carries a risk the Medigap column doesn't: your $0 premium is subsidized by a benchmark structure CRFB says is overpaying insurers by hundreds of billions, and that structure is under active scrutiny. If Congress or CMS tightens it, the adjustment lands on your benefits, not a line-item premium increase you'd catch immediately. Medigap's cost is higher and more visible today, but it's contractually locked regardless of what happens to MA benchmark rates. We've run this exact comparison with full 10-year projections in Medicare Advantage's $0 premium vs Medigap Plan G's true annual cost after hospitalization and IRMAA surcharges — worth reading in full if you're within a plan-switch window.
What to actually check before open enrollment
Don't take any of these numbers as your numbers. The overpayment story tells you MA benefits are more likely to shift than they have in recent years; the PBM story tells you formulary placement is not stable or fully rational; the IRA story tells you the $2,000 cap you're relying on is doing more protective work than most people realize. All three point to the same action: re-run your specific plan, specific drugs, and specific local network before October 15.
That means pulling your actual drug list against next year's formulary tiers, checking whether your MA plan's dental and vision allowances changed, and confirming your preferred hospital and specialists are still in-network — not assuming this year's plan performs the same as last year's. This is the exact modeling Toravine runs for you: your drugs, your income bracket for IRMAA, your local facility network, projected across the years ahead — so you're comparing your real numbers instead of national averages that may not apply to your household at all.
Start that comparison now at Toravine, before the enrollment window closes and you're locked into another year of guessing.
Sources
- In Toss-Up House District, Voters Crave Leadership To Fix Broken Healthcare — KFF Medicare
- Evidence of MA Overpayment Continues to Mount — Medicare Rights Center
- What’s at Stake in 2026: The Inflation Reduction Act — Medicare Rights Center
- Florida attorney general sues PBMs Express Scripts, Prime over alleged price fixing — Healthcare Dive
- Centene taps Fannie Mae executive as CIO — Healthcare Dive